This study aims to elucidate the effects of radiofrequency chondroplasty (RFC), a surgical technique for the treatment of damaged articular cartilage, at a microscopic scale. Here we report about two aspects of the study – a morphological analysis of the treated surface using nonlinear microscopy and Raman spectroscopy, and an investigation into changes in permeability to large and small molecules. Cartilage samples were obtained from 14 total knee replacement surgeries, which were first treated in vivo with a RFC wand (Arthrocare) using standard arthroscopy technique. Samples for the morphological study were imaged for endogenous fluorescence and collagen, and then imaged using a scanning Raman spectroscope. Samples for the permeability study were incubated in medium containing either Rhodamine or fluorescein labeled albumin, before being sectioned and imaged under a confocal microscope. The morphological study revealed a strong increase in fluorescence in the surface 10 µm, and depletion in collagen signal in the same region, which restores linearly over the adjacent 20–30 µm. Raman spectroscopy showed a spike in β-carrotein in the highly fluorescent surface. Permeability studies show a decrease in permeability to water and an increase in permeability to large molecules, suggesting a remodelling of matrix pores and implications for cell nutrition.Aim
Methods
To incorporate magnetic resonance (MR) image data in a finite element (FE) model to estimate intervertebral disc stress as a function of posture. Determining the stresses on the intervertebral discs is important for understanding disc degeneration and developing treatment strategies. The effect of different postures on disc stress has previously been investigated through disc pressure measurements and through computational modelling. Kinematic data derived from MR images and used in an FE model may provide a non-invasive way of assessing a wide range of subjects and postures.Purpose of the study
Background
